Among the causes for damage in crops are insects, mites and other animals, fungi, bacteria and viruses, nematodes, nutrient deficiencies and non-parasitic conditions (like weather). Many farmers are sufficiently experienced to recognize these causes. However, sometimes they are less obvious. This booklet intends to be a tool to determine causes of crop damage.
For each of the possible causes for crop damage the booklet explains the details: symptoms, origin and spread, and control. Many drawings clarify the text. Special attention is given to biological methods of curing the disease, like sterilization by steam, or crop rotation; chemicals can have effects worse than the disease itself.
The booklet provides exercises to test ones knowledge. It gives suggestions for further reading, useful addresses, and a glossary. One appendix helps identify general symptoms of damage; the second is useful identifying causes in affected plant parts, and the third explains symptoms of nutrient deficiencies. Also a form is added to describe the damage in crops, so that a Plant Research Station can help identify the cause.